Lachrymatory gas



o ESTATES PATENT OFFICE.

HERBERT H. DOW. OF MIDLAND, MIOHIGAN, ASSIGNOR TO THE-DOW CHEMICAL COMPANY, OF MIDLAND, MICHIGAN, A CORPORATION OF MICHIGAN,

LACHRYMATORY GAS.

amaze.

No Drawing.

' To all whom it -may concern:

-Be it known that I, HERBERT Dow, a citizen of the United States, and a resident of Midland, county of Midland, and State of Michigan, have invented a new and useful Improvement in Lachrymatory Gases,,

.lachrymatory efi'ect, is not necessarily confined to military operations or active warfare, but such compositions may be a'dvan-, tageously employed as a means for preventing burglaries, and particularly for protecting safes and vaults. Thus it has even been proposed to' automatically release such a composition in the vicinity of a safejor vault upon the latter being tampered with, the result being to intimidate, if not. to completely disable, the burglar.

The object of the.:present invention is to provide a suitable chemical composition for use inthe manner stated, one'of the conditions of such' use being that the composition shall not decompose on standing, and another being that no fire risk shall attend its use or storage. To the accomplishment of the foregoing and related ends, the invention, then, consists of the ingredients hereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail one approved combination of ingredients embodying my invention, such disclosed means constituting, however, but one of various forms in which the principle of the invention may be used. 1

Probably the most satisfactory and generally. used chemical for producing a lachrymatory GH Br) While the latter is not sufiiciently stable for a use suchas referredv to above. I

have found that either alcohol, preferably ethyl alcohol (CH .CH .OH), or tetrachlor-ethylene- (C CL), or a mixture of the two, will serve satisfactorily as a stabilizing ingredient to prevent such decomposition of the brom-acetone on standing. In

addition to such stabilizing ingredient, 'I also add a flash-point reducing ingredient which is neutrah so far'as any chemical re- Specification of LettersPatent.

'efi'ect is. brom-acetone (CH .CO.

Patented Apr. 4, 1922.

Application filed March 31, 1920. Serial No. 370,262.

action with the brom-acetone and such stabilizing ingredients or ingredients is concerned, but which will eliminate or so lower the flash-point of the brom-acetone as to practically remove all fire hazard. As a satisfactory ingredient for this last ment oned purpose, I- employ carbon tetrachloride (GU1 or other equivalent halogenated hydrocarbon such as chloroform (CHCLQ and di-chlorsmethane (CH CLQI 'A relatively small amount of the stabi-lizing ingredient mentioned is required, while of such flash-point reducing agent, the quantity employed will be .gaged by the degree of safety-desired. Preferably my improved composition of matter will consist of the foregoing "ingredients in approximately the following proportions, viz. brom-acetone 40 per cent, alcohol 10 per cent, tetrachlor ethylene 10 per cent, and carbon tetrachloride 40 per cent. All the foregoing inv gredients are readily miscible, and, other Y than by dilution, they have no counter or negative reaction on the desired lachrymatory eii'ect of the brom-acetone. At the same time they measurably increase the volatility of the active agent.

A convenient container for a tear gas of the foregoin'g'composition may be made of cellulose actetate, since this material is not soluble in b-rom-acetone or the other ingredients stated, and will be of flexible or'semiflexible character, thus rendering the container less likely to be broken accidentally.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the materials employed, provided the ingredients stated by any of the following claims or the equivalent of such statedingredients be employed.

I therefore particularly point out and distinctly claimas my invention 1. A composition of matter for producing a lachrymatory effect, including promacetone, and a fiash-point reducing ingred ent. 2. A composition of matter for producing a la-chrymatory effect, including brom-acetone and a halogenated hydrocarbon adapted to reduce the flash-point of said bromacetone.

3. A- composition of matter for producing a lachrymatory efiect, including brom-acetone and carbon tetrachloride.

4, A composition of matter for producing a lachrymatory effect, including brom-acetone, a stabilizing ingredient, and a flashpoint reducing ingredient.

5. A composition of matter for producing a lachrymatory efieet, including bromacetone, alcohol, and a halogenated hydrocarbon.

6. A composition of matter for producing a lachryma-tory effect, including brom-acetone, alcohol. and carbon tetrachloride.

' 7. A composition of matter for producing v a lachrymatory eflect, including brom-acetone, alcohol, tetrachlor-ethylene'and carbon tetrachloride.

8. A composition of matter for producing a lachrymatory efiect, consisting of the following ingredients in approximately the proportions stated, viz. brom-acetone 40 per cent, alcohol 10 per cent, tetrachlor-ethylene 10 per cent, and carbon tetrachloride 40; per cent.

HERBERT H. DOW. 

